There is conventionally known a fixing device that includes a heating unit; a pressure roller; a frame; and an urging mechanism. The heating unit includes a heater. The pressure roller conveys a sheet while nipping the sheet in cooperation with the heating unit. The frame supports the heating unit such that the heating unit is movable in a direction toward and away from the pressure roller. The urging mechanism urges the heating unit toward the pressure roller.
More specifically, in this fixing device, the frame has a pair of side walls disposed on respective sides of the pressure roller in an axial direction thereof. Each side wall has a first wall portion and a pair of second wall portions to provide a generally U-shape. The first wall portion rotatably supports axial end portions of the pressure roller through bearing members. The pair of second wall portions protrudes from the first wall portion toward the heating unit, and supports the heating unit, interposing the heating unit therebetween in a sheet conveyance direction. Each axial end portion of the heating unit is interposed between the respective pair of second wall portions. Hence, the heating unit is fixed in position with respect to the pressure roller in the sheet conveyance direction.